Working with diverse student populations productively depends on teachers and teacher-educators recognising and valuing difference. Too often, in teacher-education programs, when markers of identity such as gender, ethnicity, 'race', class are examined, the focus is on developing student-teachers' understandings of how these discourses shape learner identities and rarely on how these also shape teachers' identities.This paper reports on a research project that explored how student-teachers understand ethnicity and socio-economic status. In a preliminary stage of the research, we asked eight third-year teacher education students who had attended mainly Anglo-Australian middle-class schools as students and as student-teachers, to explore their own ethnic and classed identities. The complexities of identity are foregrounded in both the assumptions we made in selecting particular students for the project and in the ways they constructed their own identities around ethnicity and class. In this paper we draw on these findings to interrogate how categories of identity are fluid, shifting and ongoing processes of negotiation, troubling and complex. We also consider the implications for teacher education.